SB 945 
.B48 G3 
Copy 1 



UNITED STATES DEPARTMENT OF AGRICULTURE 

BULLETIN No. 834 



Contribution from the Bureau of Entomotogy 
L. O. HOWARD, Chief 




4'>^''^^U 




Washington, D. C. 



PROFESSIONAL PAPER 



May 19, 1920 



BLACK GRAIN-STEM SAWFLY OF EUROPE^ IN 
THE UNITED STATES. 

By A. B. Gahan, Entomological Anfiistant, Cereal and Forage Insect Investi- 
gations . 



CONTENTS. 



V Page. 

Introduction 1 

nistory of discovery of the insect in 

America 2 

Common name of the species 3 

Distribution 3 

Old-World distribution 3 

Distribution in America 4 

Probable future distribution in 

America o 

Food plants 5 

Food plants in Europe 5 

Food plants in America (> 



Page. 
Synonymy and description of Tra- 

clielus tabidus 7 

Adult 8 

Overwintering larva g 

Manner of work ajid probable life 

history q 

Extent and character of injury n 

Parasites J2 

Suggestions for control 12 

Literature cited 14 



INTRODUCTION. 

That another exotic insect with possibilities for damage to agricul- 
ture has become established in America, that it is now quite widely 
distributed, and that it has already begim to make itself felt was 
brought to light during the summer of 1918. In view of its probable 
future importance and the consequent desirability of learning as soon 
as possible the facts about its distribution, food plants, and injuri- 
ousness, it is deemed exj)edient to bring the matter to the notice of 
entomologists and others through publication at this time of such 
information as is at hand.- 



^ Tracheitis tcibidiis (Fab.). 

2 The writer is Indebted to Miss Margaret Pagan, of the Bureau of Entomology, for 
compilation of the appended bibliography ; to Messrs. W. R. McConnell, P. R. Myers, and 
W. J. Phillips, also of the Bureau of Entomology, for reared and collected material and 
notes which were invaluable in establishing the identity and distribution of the insect ; 
to Dr. J. Chester Bradley, of Cornell University, for larval material of Cephus pygmaeus 
as well as useful suggestions regarding characters for separating the larvie ; and to 
Messrs. S. A. Rohwer and Wm. Middleton for numexous helpful suggestions. 
148465°— 20 — Bull. 834 1 



V^ 



2 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

HISTORY OF DISCOVERY OF THE INSECT IN AMERICA 

Specimens of a sawfly were collected by C. W. Jolinson at River- 
ton, N. J., some time prior to 1899, the exact date unknown. These 
were submitted to Dr. W. H. Ashmead for determination and pro- 
nounced by him a new species, to which he gave the manuscript name 
of Calameuta jolinsoni. Under this name, misspelled Calamenta john- 
soni, the record was published, without description, in the second edi- 
tion of Insects of New Jersey, by John B. Smith (39) .^ A description 
based on these specimens was later published by Ashmead (40) , Sub- 
sequently the type specimens were examined by Dr. J. Chester Brad- 
ley, who recognized in them the European species Trachelus tahidus 
Fabricius, and under this corrected name the record of the original 
collection was again published in the third edition of Insects of New 
Jersey (45). At that time, and for some time thereafter, nothing 
was known of the food plants of the sj)ecies in this country. Such 
European records as existed were in the Russian literature, and be- 
cause of difficulty in translation were largely overlooked. Since 
Trachelus tdbidus was not known to be causing any injury, no par- 
ticular attention was paid to it. 

During the summer of 1918 a complaint was received by the Bu- 
reau of Entomology from a correspondent at Gaithersburg, Md., re- 
garding the work of some insect which had caused his ripening wheat 
to fall badly, and the writer was detailed by Mr. W. R. Walton, in 
charge of Cereal and Forage Crop Insect Investigations, to investi- 
gate the outbreak. 

Specimens of the injured stalks were received from the corre- 
spondent, some of which proved to contain larvae of what was readily 
determined as a species of Cephidae. The insect was at first thought 
to be either Cephus fygTnaeus Linnaeus or Cephus cinctws Norton. 
The former species had been known in the vicinity of Ithaca, N. Y., 
many years before, but so far as the records indicated, had succeeded 
in spreading but little from the point of original infestation and had 
never been recorded as seriously injurious. Cephus cinctus was 
known only from the western United States and was not believed to 
occur east of the Mississippi River except for a few localities in 
Michigan. 

When the Maryland infestation was brought to the attention of 
Mr. S. A. Rohwer, specialist on sawflies, of the United States Depart- 
ment of Agriculture, Bureau of Entomology, he at once suggested 
the possibility that the insect might be Trachelus tahidus Fabricius. 
Several adult specimens of this species in addition to those originally 
taken at Riverton, N. J., were in the United States National Museum. 
These, as shown by the labeling, were collected at two or three differ- 

1 Numbers in parenthesis refer to " Literature cited," p. 14. 



'Vp) BLACK GRAIN-STEM SAWFLY, 



ent points in Maryland and Pennsylvania. The fact that Tracheitis 
tahkhis was thus known to occur in the region of the infestation and 
that it was the only species of Cephidae known to occur there which 
would be likely to have the habit attributed to this one, at once es- 
tablished a strong probability that it was the species concerned. 
This suspicion was confirmed when Messrs. W. R. McConnell and 
P. R. Myers, who had been engaged for several years in investigating 
the insect enemies of wheat and other cereals for the Bureau of Ento- 
mology in Maryland and Pennsylvania, turned over to the writer all 
of the sawfly material which they had secured from that region. 
This material all proved to be Traclielus tabklus and included sev- 
eral specimens which had actually been reared from wheat stubble 
in breeding cages, as well as numerous specimens collected by sweep- 
ing wheat. The reared material left little doubt as to the identity of 
the depredator in question. Reference to the European literature, 
especially that by a number of the more recent Russian entomologists, 
regarding Trachelus tabldus, cleared up whatever lingering doubts 
might still have existed. 

The manner in which this insect became established in America is 
unknown and probably will remain a mystery. Any surmise as to 
the probable manner of introduction would be valueless and since it 
could have no effect upon the fact that it probably has come to remain, 

is omitted. 

COMMON NAME OF THE SPECIES. 

In Russian literature this species is referred to as the black sawyer 
or black sawfly because of its nearly uniform black color. The writer 
has ventured to modify this name to some extent by calling it the 
black grain-stem sawfly. This name is descriptive of the insect as 
well as of its habit and at the same time minimizes the possibility of 
confusion with other black species of sawfly. 

DISTRIBUTION. 

OLD-WORLD DISTRIBUTION. 

Andre (33) records the species as occurring in England, France, 
Sweden, Spain, Germany, Italy, Algeria, and Syria. Cameron (35) 
in his " Monograph of the British Phytophagous Hymenoptera " 
gives practically the same distribution, omitting France. Konow 
(42) in Genera Insectorum cites middle and southern Europe, Algeria, 
and Asia Minor. Several writers, including Shtchegolev (49) , Kurd- 
jumov (48), Uvarov (50, 54), Zolotarevsky (53), and Borodin (52), 
have recorded it more recently from central and southern Russia, 
while Kulagin (47) states that Ce/plms pygmaeus and Trachelus 
tahldus have been recorded from 26 different governments of Russia. 



4 BULLETIN 834, IT. S. DEPARTMENT OF AGRICULTURE. 

From this it will be seen that the species occurs in all three Old 
World continents, being present throiighont most of the middle and 
southern European countries, southeastern Asia, and northern xVfrica. 
It is probable that it will eventually be found to be present through- 
out most of the remaining regions where Avheat is gi'own in Europe 
and eastern Asia, as well as northern Africa. 

DISTRIBUTION IN AMERICA. 

The present distribution in America, gleaned from the writer's in- 
vestigations, the records of Messrs. McConnell and Myers, which 
were kindly placed at his disposal, specimens in the United States 
National Museum, and a note furnished by Dr. J. Chester Bradley, 
includes localities in six States, viz : New Jersey, Virginia, Delaware, 
Maryland, Pennsylvania, and New York. 

The localities where the insect is at present known to occur, to- 
gether with the date of collection and the name of collector, are as 
follows : 

Riverton, N. J., adults collected by C. W. Johnson, May 29 (year not given 
but prior to 1899) ; East Falls Church, Va., hibernating larva; in wheat and 
rye stubble, A. B. Gahan and S. A. Rohwer, collectors, August 6, 1918 ; War- 
renton, Va., larvae collected in August, 1918, by W. J. Phillips; Harrington, 
Del., larvae collected in wheat stubble by W. R. McConnell ; AVolfsville, Md., 
adults swept in clover field by J. A. Hyslop, June 6, 1914; Hagerstown, Md., 
adults swept from wheat by P. R. Myers and W. R. McConnell, May 15, May 25, 
June 4, 1915, and May 24 and June 8, 1916 ; Hagerstown, Md., adults i-eared 
from wheat stubble by P. R. Myers, May 10, 1916, and by W. R. McConnell, 
May 3, 1917; Taylors Island, Md., adult reared from wheat stubble by W. R. 
McConnell, March 21, 1917; Great Falls, Md., adult swept by Frederick Knab, 
May 24, 1914; Germantown, Md., larvse injuring wheat received from a cor- 
respondent by the Maryland State College of Agriculture, and recorded under 
the name of Ccphus pyymaeus in Reiwrt of Maryland State Horticultural 
Society, 1914 ; Gaithersburg and Laytonsville, Md., hibernating larvse collected 
by A. B. Gahan in wheat stubble, July 22, 1918 ; College Park, Md., hibernating 
larvse in wheat by A. B. Gahan, July 24, 1918; Berwyn, Md., hibernating 
larvse in rye stubble collected by A. B. Gahan, July 30, 1918; Laurel, Md., 
hibernating larvse in wheat stubble, by A. B. Gahan, July 26, 1918 ; Towson, 
Md., hibernating larvse in wheat stubble, by A. B. Gahan, August 2, 1918 ; 
Warfordsburg, Pa., adult reared from wheat stubble by P. R. Myers, June 5, 
1916; Hunters Run, Pa., adult reared from wheat stubble, W. R. McConnell, 
May 7, 1918; West Chester, Pa., adult collected by H. L. Parker, June, 1915; 
Linglestown, Pa., adults collected by H. B. Kirk and A. B. Champlain, May 26, 
1908 ; Herndon, Pa., adults, collector unknown, June 6, 1907 ; State College, Pa., 
adult swept in clover by W. R. McConnell, May 30, 1911; Carlisle, Pa., larvse 
collected July 23, 1918, by C. C. Hill, and July 31, 1918, by W. R. McConnell ; 
Mt. Holly Springs, Pa., larvse collected in wheat stubble, June 25, 1918, by 
McConnell and Myers. 

In addition to these records Dr. J. C. Bradley states that he has 
seen one adult specimen in the collection of the Brooklyn Museum 
fi'om Long Island, N. Y. 



BLACK GEAIN-STEM SAWFLY. 



These records probably indicate only approximately tlie present 
distribution (fig. 1) of the species. A more extended investigation 
will be necessary to establish the exact limits. The records are 
sufficient to establish a probability that it already occurs over the 
greater part of Virginia, Maryland, Pennsylvania, New Jersey, and 
Delaware, and it is j)ossible that "West Virginia, eastern Ohio, 
southern New York, and even some of the New England States may 
already be included within its range. 

PROBABLE FUTURE DISTRIBUTION IN AMERICA. 

Judging by its wide distribution in the Old World, as well as by 
the character of localities already included within its range in this 
country, including both 
tidewater and mountain 
districts, there seems little 
reason to doubt that the 
species will eventually 
spread over all the wheat- 
growing sections of the 
eastern and central United 
States. "Wliether it will 
accommodate itself to the 
arid and semiarid wheat- 
growing districts of the 
West is matter for specu- 
lation. The average pre- 
cipitation of this region 
does not differ greatly 
from that of southern 

Russia, where the species seems to be at its worst. The mean 
temperatures of the two regions probably are not widely differ- 
ent. It seems possible, therefore, that unless some other climatic 
or physical factor intervenes, the species may spread eventually from 
coast to coast. That it will spread northward into Canada may be 
doubted, since in Europe, although recorded from Sweden, it seems 
not to occur generally in the colder northern portion. 

FOOD PLANTS. 

FOOD PLANTS IN EUROPE. 

In European literature, with one exception, the records of food 
plants of Trachetus tabidus are by Eussian entomologists. Rudow 
(43), in speaking of Cephus satyr^s Panzer, C. nigrlnus Thomson, C. 
pallipes Klug, C. arundinis Giraud, and C. tabidus Fabricius, makes 
the general statement that in southern Europe these species live in 




Fig. 1.- 



-Present known distribution of Tracheitis 
taMdus in America. 



6 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

Triticum repens, Bromus, Holcus, and reeds or bulrushes, without 
specifying which plants serve as host plants for the different species. 
The record is, therefore, too general to be of much value in the 
present circumstances. 

The Russian records are more specific and apparently all refer 
to infestation of small-grain crops. Shtchegolev (49) records the 
species as a serious pest of wheat; Borodin (52) reared it together 
with Cephws pygrnaeus from barley and both spring sown and 
winter sown wheat; Kulagin (47) states that it infests rye and wheat 
in the Province of Taurida. Various other Russian writers, includ- 
ing Uvarov (50) (54),Zolotarevsky (53), and Kurdjumov (48), have 
recorded the species as attacking the grain crops, principally wheat. 

FOOD PLANTS IN AMERICA. 

Thus far in America only wheat and rye are known to serve as 
food plants. Only two instances of its occurrence in rye are known, 
both observations having been made by the writer during the past 
summer. In each instance in which it was found in rye only one 
infested stalk was located in the field, although careful search was 
made. Although several fields of oats stubble were examined more 
or less carefully, no infestation of this crop was observed even when 
the oats were in close proximity to infested wheat fields. No oppor- 
tunity to examine barley has offered itself. 

It appears fairly certain that of the cultivated grain crops wheat 
will prove to be its preferred food plant. As stated elsewhere, the 
writer was able to find larvse in varying quantities in every wheat 
field visited in the course of the limited investigation carried on 
during the summer of 1918. 

That the species eventually will be found to infest plants other 
than the small grains is possible. The related species, Cephus 
cinctus, which also infests the small-grain crops in our Western 
States, is known to have a long list of food plants among the coarser 
grasses, both wild and cultivated. Cephus cinctivs is believed, how- 
ever, to be a native species whose original food plants were wild 
grasses and whose habit of attacking the cultivated grains has been 
induced through elimination or reduction of its natural source of 
food supply by the development of agriculture. Present informa- 
tion indicates that the natural food plants of Trachelus tabidus are 
the small grains, although it may yet prove to have other hosts in 
Europe. It is doubtful whether the species which has been trans- 
planted from its native habitat to America will find it possible to 
develop in our native grasses. Only future investigation can de- 
termine. The possibility of its being able to maintain itself upon 
grasses other than the small grains should be borne in mind, and 



BLACK GRAIN^-STEM SAWFLY. 7 

such grasses as Elymus, Bromus, Agropyron, and in fact any of the 
cultivated or wild grasses whose seasonal development is such as to 
provide a succulent stem of sufficient size to accommodate the larvae 
during the period of larval activity, May and June, should be viewed 
with suspicion. 

SYNONYMY AND DESCRIPTION OF TRACHELUS TABIDUS. 

Since the original description by Fabricius (1), the name has 
undergone a number of generic transfers, and it has been redescribed 
or referred to under several specific names. 

It is the opinion of the writer, however, that some of the pub- 
lished synonymy is incorrect. Trachelus haemorroidalis Jurine (17) 
is listed as a synonym by Dalla Torre (38). The figure given by 
Jurine is not that of tahldus^ but is undoubtedly identical with 
Cephus analis Khig (12). The latter name is generally recognized 
by European writers as a synonym of haemorrhoidalis Fabricius (2). 
Konow (41) includes Sirex macilentus Fabricius (9), Cephus erheri 
Damianitsch (30), and Cephus vittatus Costa (32) as color varie- 
ties of tdbldus. The large number of specimens of tabidus examined 
bj' the writer show no variation in color comparable to Tnac'dentus 
as illustrated by Coquebert (10), and since other European writers 
generally have recognized this as a distinct species it has been ex- 
cluded from the synonj^my. Cephus erheri is described as having 
the third to seventh dorsal abdominal segments banded with yellow, 
the band on the third segment interrupted, while the third to ninth 
ventral segments are said to be margined with yellow laterally. In 
no specimen of tabidus examined by the writer is there any indica- 
tion of a dorsal band of yellow on the abdomen nor are the ventral 
segments margined with yellow. Like macilentus^ this species is 
therefore excluded from the synonymy. The description of vittatus^ 
on the other hand, agi'ees closely with tahidus^ and there seems to be 
no good reason why it should not be considered a pure synonym in- 
stead of a color variety. 

Following is the complete synonymy of Trachelus tabidus as 
understood by the writer: 

Trachelus tahidus (Fabricius) Jurine. 

Sirex tabidus Fabricius (1), (2), (4).— Villers (5).— Linne (6).— Christ 
(8).— Fabricius (9).— Coquebert (10).— Walckenaer (11).— Rossi 
(19).— Herricli-SchafEer (26).— Dumeril (29). 

Tenthredo longicollis Fourcroy (3). — Villers (5). 

Astatus tahidus Klug (12). — Panzer (15). 

Cephus tabidus Fabricius (13). — Latreille (14).— Panzer (16).— Latreille 
(18).— Lepeletier (20).— Stepliens (23).— Hartig (24).— Blancliard 
(25).— Lucas (27).— Costa (2S).— Tasclienberg (31).— Andre (33).— 
Cameron (34), (35).— Magretti (36).— Costa (37).— Dalla Torre (38). 



8 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE, 

Trachclus iabkZws Jurine (17). — Curtis (22). — Konow (41), (42). — Rudow 
( 43 ) .— Kokujev ( 44 ) .— MacGillivray i"^) .— Kliolodkovsky ( 46 ) .— 
Kulagin (47). — Kiirdjumov (48). — Shtcliegolev (49). — Uvarov (50). — 
Borodin (52).^ — Zolotarevsky (53). — Uvarov and Glazunov (54). — Mac- 
Gillivray (55).— Howard (56). 

Cephus nigritus Lepeletier (20). 

Cephus vittatus Costa (32). 

Calamenta johnsoni Aslimead (39). 

Calamcuta johnsoni Ashmead (40). 

Cephus pygmaeus Cory (51), not Linnaeus. 

ADULT. 

Female. — Long and slendei', v^itli abdomen somewhat compressed. Antennae 
longer than thorax, thickened at apex, third joint slightly shorter than fourth, 
third to eighth joints four to five times as long as thick, those beyond eighth 
gradually shortening, the ones in thickened portion of antennte subequal and 
not longer than broad ; clypeus truncate at apex, with sharp lateral angles ; 
occiput concave ; greatest width of posterior orbit about equal to greatest trans- 
verse diameter of eye; pronotum elongate, nearly as long as broad, broadest 
at posterior margin, its sides more or less concave; mesoscutum and scutellum 
subequal in length ; middle and hind tibiae each with two apical spurs and 
normally each with two (sometimes one only) superapical spurs located at 
about the apical one-third of tibiae ; abdomen much longer than head and 
thorax, subcompressed, with sheaths broad and slightly thickened at apex. 
Polished black ; mandibles except at apex, small spot below tegulae, apex of 
front femora within, inper side of front tibiae for its whole length, spot at 
apex of median femora in front, a broad longitudinal stripe along lateral 
margins of dorsal segments, a lateral spot on seventh ventral segment, and a 
narrow marginal stripe on basal part of sheaths yellow ; wings subhyaline, 
nervures and stigma black. (See PI. II, A.) 

Male. — Similar to female in general appeai'ance and color. Last visible 
ventral segment of abdomen prominent and extending beyond last dorsal seg- 
ment ; two ventral segments before last visible segment each with a broad, 
deep, horseshoe-shaped depression, within which is a transverse row of stiff, 
erect bristles. (See PI. II, B.) 

The only species occurring in America, so far as known, with 
which this species is likely to be confused are Cephus cinctus Norton 
and Cephus fygrrmeus Linnaeus. The female may be readily dis- 
tinguished by the fact that in both cinctus and fygmaeus the sheaths 
are narrower at apex than in the middle, and the dorsal segments 
are banded apically with yellow. The legs are also more largely 
yellowish. The male of tahidus differs from the males of the other 
two species in the presence of the horseshoe-shaped depression on 
the two ventral segments as well as by the color characters pointed 
out for the female. 

OVERWINTERING LARVA. 

Body subcylindrical, yellowish white in color, 7 to 9 mm. in length, thoracic 
region slightly thicker than abdominal region. Living larvae more or less tinged 
with greenish due to body contents. 

Head pale yellow, its dorso-ventral length 1.1 mm., breadth 1.1 mm. Anten- 
nae 5-jointed, tapering to a point at apex, more or less fuscous in color. Man- 
dibles four-toothed, brownish, their apices nearly black ; labrum, sutures about 



Bui. 834, U. S. Dept. of Agriculture. 



Plate I. 






The black Grain-Stem Sawfly of Europe in the United States. 

A Trachelui tabids: Lateral view of apical segments of larva; B, Ceplius cinctus: 
tate4l view of apical segments of larva; C, Cephus pygmaem: Lateral view of apical 
segments of larva. 



Bui. 834, U. S. Dept. of Agriculture. 



Plate 1 1 . 





Trachelus tabidus. 

A, Adult female: a, Lateral view of female abdomen. B, Adult male: 6, Ventral view of male 

abdomen. 



BLACK GRAIN-STEM SAWFLY. 9 

clypeus, and articulations of mandibles brownish. Thoracic legs small, papilli- 
form, and pale brownish. Dorsal abdominal segments triannulate; pleura 
prominent; ventral segments triannulate; prolegs absent. (For further de- 
scription see Plate I, A, and key to larvae.) 

Larvae of this species are apt to be confused with those of Cephus 
'pygmaeus and C. cinctus. All three species infest the small grain 
crops in practically the same manner, have very similar biologies, 
and superficially resemble one another closely. The following key in 
conjunction with the accompanying figures will, it is believed, make 
it possible to recognize them : 

KEY FOR SEPARATING GEAIN-INFESTING SAWFLY LAEVwE- 

1. Dorsal anal lobe of the tenth tergite viewed from the side triangular, slop- 

ing gradually from base to apex, the anterior end of lobe much thicker 
than the posterior end which is more or less acute. Spines on the anal 
prong each arising from a small, more or less chitinized tubercule and 
closely grouped about the apex of the enlarged fleshy portion just 
basad of the short chitinized apical ring. Eighth and ninth tergites ap- 
parently- glabrous 2. 

Dorsal and lobe viewed from the side not triangular, not sloping gradu- 
ally from base to apex but convexly rounded, the posterior end of the 
lobe as thick dorso-ventrally as the anterior end and nearly perpendicu- 
lar. Anal prong completely encircled by two irregular series of widely 
separated, short, stiff spines which do not arise from chitinized tubercules. 
Eighth and ninth tergites each with a transverse row of distinct short 
hairs. (See I'late I, A.) Trachelus tabidiis Fab. 

2. Anal prong terminating in a short chitinized ring which is not as long as 

broad. Spines basad of chitinized ring few in number, confined to a single 
transverse row on the dorsal surface. Dorsal, lateral, and ventral lobes 

all sparsely hairy. (See PI. I, A.) Cephus pygmaeus Linn. 

Anal prong terminating in a chitinized tube-like process which is distinctly 
longer than broad. Spines basad of the apical tube-like process numerous, 
arranged in two irregular contiguous series completely encircling base of 

tube. Anal lobes all more distinctly hairy. (See PI. I, A.) 

Cephus cinctus Nort. 

MANNER OF WORK AND PROBABLE LIFE HISTORY. 

Observations by the writer supplemented by those of McConnell 
and Myers, and confirmed in part by Kulagin (47) indicate that 
the life history of Trachelus tahidus does not differ greatly from that 
of the western grass-stem sawfl}^, Cephus cinctus. The early stages 
have not yet been observed in this country. Collections of adults 
in the field indicate that egg-laying takes place during the period 
May 15 to June 10. Some of the emergence records for reared 
specimens show somewhat earlier dates than May 15, but since 
these were obtained under the abnormal conditions of the labora- 
tory they may be disregarded. Kulagin indicates about the same 
period for egg-laying in Russia. 
148465°— 20— Bull. 834 2 



10 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

The eggs are inserted in a slit made by the female in the stem 
some distance above the ground. The young larvae burrow down- 
ward through the pith of the stem, hollowing it out to the base. 
The larvae apparently attain full growth at about the time the 
grain is ripe. At the time the writer's investigations were begun, 
July 22, they were full grown and had evidently gone into hiber- 
nation. The fully-developed larvae were, at this time, located at 
the extreme base of the stem, encased in a silken tube or lining 
to the burrow, this tube being two or three times the length of 
the larva and filling the hollow straw completely from about the 
surface of the ground downward. Above this silken tube the bur- 
row is completely closed by a wad of frass. Before this wad of 
frass is put in j^lace the larva almost completely severs the stem 
from the inside, this cut in nearly every case being at or very^ 
near the surface of the ground and usually a little above the 
first node on the stem where the surface roots put out. In making 
this cut just enough of the epidermis of the straw is left unsevered 
to attach it lightly and allow it to stand erect. In consequence of 
this cut the first slight bending of the ripened straw, as by a strong 
wind, causes it to snap off and fall. 

Straws cut off by the insect are easily distinguishable from those 
severed by the harvester. The cut is exactly transverse to the stem 
and the ends of both the stub which remains in the ground and the 
fallen straw are distinctly concave or funnel-shaped. This appear- 
ance is so characteristic that one can readily detect the presence of 
the pest in a field by simply examining the ends of the fallen straws. 

The hibernating larva, as already stated, is to be found in the 
stub of the wheat stalk remaining in the ground. Since this stub in 
most cases barely extends to the surface of the soil (sometimes a 
little above the surface) , it is not always an easy matter to locate it. 
The fallen straws sometimes remain slightly attached on one side to 
the stub, and in such instances one can locate the infested stub by 
following the straw to its base. When the straw is completely de- 
tached, as is usually the case in a field that has been harvested, it is 
often necessary to search for some time before the stub containing the 
larva can be located. 

The greater part of the insect's life cycle is apparently spent as a 
hibernating larva, this period extending from about the time the 
wheat is ripe enough to cut until some time the following spring 
when the larva changes to the pupa. Just when this change takes 
place has not been ascertained, but the pupal state is probably of 
short duration, as in Ceflius cinctus; if so, the change to the pupa 
jDrobably occurs in the latter part of April or early part of May. 
Adults, as already stated, are to be found in the fields during the 
latter half of May and early June. 



BLACK GRAIN-STEM SAWFLY. 11 

In the case of one male specimen reared from wheat stubble bj'^ 
McConnell, the insect was collected as a larva September 30, 1915, 
and emerged as an adult May 3, 1917. This shows that under some 
conditions the life cycle may be extended over a two-year period. 
Such instances are probably rare under natural conditions, but the 
record indicates a high degree of adaptability on the part of the 
species for overcoming unfavorable conditions. 

EXTENT AND CHARACTER OF INJURY. 

Shortly after receipt of the complaint from Gaithersburg, and be- 
fore the identity of the insect was known, the writer was detailed to 
visit the locality and investigate the nature and extent of the damage. 
Accordingly, on July 22, 1918, the farm of the correspondent, Mr. 
Beverly E. Codwise, was visited. It lies about 3 miles north of 
Gaithersburg on the road to Laytonsville, Md. Unfortunately the 
infested fields had already been harvested, making it practically im- 
possible to estimate the extent of the actual injury. It was evident, 
however, that there had been an appreciable loss due to falling of the 
grain, so that it could not be picked up by the binder. The writer 
was informed that comment by passers-by on the large amount of 
grain missed by the binder had first called attention to the injury 
and caused the investigation which resulted in the sending of samples 
to the Bureau of Entomology. 

Three other farms in the neighborhood of Gaithersburg were 
visited, on each of which the pest was located. Subsequently wheat 
fields in various other localities in Maryland and one in Virginia were 
visited, with the result that in every wheat field examined the insect 
was found to be present in varying abundance. 

No actual counts of infested straw were made by the writer in any 
of the fields to ascertain the percentage of infestation. It was roughly 
estimated that in some of the worst cases the infestation amounted to 
4 or 5 per cent. In most of the fields the infestation was much less 
than 4 per cent. Messrs. McConnell and Myers did make counts 
of the infested stubble on a small number of experimental plats and 
other fields of wheat • at Carlisle and Mount Holly Springs, Pa., 
with the results showing an infestation varying from 4.36 per cent 
on one of the plats to 0.26 per cent on another, the average from all 
counts being 1.75 per cent. 

That a 4 per cent infestation of stubble necessarily indicates a 4 
per cent loss in the crop is not probable. The insect apparently 
chooses only well-developed and vigorous stems in which to oviposit, 
and some of these infested stems are known to develop at least par- 
tially filled heads. Just what the loss, if any, from failure of the 
heads on infested stalks to fill properly may be, remains to be de- 
termined. 



12 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

It is certain that serious loss may and does occur because of fall- 
ing of the grain due to the cut made by the larva preparatory to 
hibernation. The extent of this loss will in all probability depend 
in some degree upon weather conditions during the period of ripening 
of the grain. A heavy wind or severe storm at this time would cause 
most of the infested grain stalks to break off and fall so that they 
would not be picked up by the harvester. In the absence of such 
a wind or storm, the loss would undoubtedly be much less, but even 
with favorable conditions a certain percentage of the infested stalks 
would be broken off by the harvester reel and fall in front of the plat- 
form. 

Kulagin (47) states that losses in Russia due to this species and 
Cephas pygmaeus are estimated at 14 to 20 per cent, although more 
severe in some cases. Shtchegolev (49) also reports 15 to 20 per 
cent injury due to these two pests. Other Russian writers record 
severe injury without specifying the amount. Unfortunately, in 
practically every instance these writers treat of th^ injury by 
Cephm pygma&m and Trachelus tabidus collectively, without indi- 
cating how much of the damage is chargeable to each. This is no 
doubt due to the fact that they have been unable to distinguish the 
larvae of the two species. Their records, therefore, do not afford 
a reliable basis for estimating the probable future importance of 
Trachelus tabidus in this country. 

PARASITES. 

In Russia two parasites of Trachelws tabidus have been recorded. 
Collyria calcitrator (Gravenhorst), an ichneumonid wasp, is ap- 
parently a common parasite of this species as well as of Ceplius 
pygmaeus. Borodin (52) records the chalcidid Arthrolysis {Picro- 
cystus) scdbricula Nees as having been reared from these two saw- 
fly pests. Neither of these species has, as yet, been found in America. 

The existence of at least one efficient parasite in America has, 
however, been established. Numerous specimens of a chalcidoid 
belonging to the genus Pleurotropis and apparently representing an 
undescribed species have been reared by Mr.. W. R. McConnell at 
Mount Holly Springs and Carlisle, Pa. So far little is known of the 
life history of the species. It emerges from the prepupal larva of the 
Trachelus at about the time of emergence of the host adults and is 
believed to be a primary parasite, solitary in" its habit. Observations 
to date are too limited in extent to form a very accurate estimate 
of the efficiency of this parasite, but in some instances at least it 
appears to exercise a considerable degree of control. 

SUGGESTIONS FOR CONTROL. 

In the present state of our knowledge of this species only sug- 
gestions of possible means of control can be given. 



BLACK GRAIN-STEM SAWFLY. 13 

Measures for control will doubtless be similar to those against 
Cefhus cinctus^ the western grass-stem sawfly, and CepJius pygmaeus. 

It is obviously impracticable to attack the insect in the egg stage 
or active larva stage, since both stages occur in the growing grain. 
The adult can not be reached by any known method. It appears, 
therefore, that control measures to be successful must either aim at 
destruction of the hibernating larva or pupa while in the stubble, 
where the insect passes the greater part of its existence, or be con- 
fined to cultural methods such as crop rotation. The fact that the 
larva is located in the part of the stem below the surface of the 
ground precludes the possibility of accomplishing anything by any 
ordinary burning of the stubble. Disking the stubble thoroughly 
as soon after cutting the grain as practicable would possibly be of 
benefit by turning the infested stubble out and thus exposing the 
larva to the action of summer heat and winter cold. The larva is 
quite hardy, however, and only experimentation will prove or dis- 
prove the effectiveness of disking. 

In Russia plowing down of the stubble as deeply as possible is 
recommended against this species as wxll as against Cephus pyg- 
Trmeus. The same treatment is recommended and has proved success- 
ful against Cephus cinctus in this country, and it seems the logical 
treatment for adoption against this species. To be effective the plow- 
ing must bury the stub containing the larva so deeply that the matur- 
ing adult will be unable to escape. Shallow plowing will not suffice, 
as the adults undoubtedly will be able to burrow their way out if 
covered with only 2 or 3 inches of soil. Deep and clean plowing, 
therefore, will be essential. The plowing may be done at any time 
between the cutting of the grain and the following spring prior to 
emergence of the adults in April or May. 

If, as now seems probable, this insect confines itself, in this coun- 
try, to the small-grain crops as host plants, there can be little doubt 
that crop rotation will prove an effective means of reducing damage 
from it. Wheat, barley, or rye should be followed by some crop 
which will not serve as a host plant, such as corn or truck crops. The 
present practice on some farms of growing wheat on the same ground 
two years in succession is distinctly favorable to the propagation of 
the pest since the adults upon emerging find themselves surrounded 
by ideal conditions for oviposition. The practice also of sowing 
grass or clover with wheat and allowing the wheat stubble contain- 
ing the larva to stand undisturbed for two seasons could hardly be 
improved upon as means of increasing the numbers of this insect. 
Any system of rotation to be effective should insure thorough plow- 
ing down of the wheat stubble and the growing of some crop other 
than a small grain following wheat. 



14 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

LITERATURE CITED. 

(1) FABRICrUS, J. C. 

1775. SYSTEMA ENTOMOLOGiAE . . . Flensburgi et Lipsiae. 832 p. 

Page 326, no. 8 : Original description under name of Sirex taiidus. 
England. 

(2) 



1781. SPECIES iNSECTORUM . . . Hamburgi ot Kilonii. Tome 1. 

Page 420, no. 13 : Brief description of Sirex tahidus, with note, " Habi- 
tat in Angliae floribus." Page 417, no. 59 : Original description of 
Tenthrcdo Tiaem-orrhoidalis. 

(3) FOUBCKOY, A. F. DE. 

1785. ENTOMOLOGiA PARisiENSis . . . Puris. Pars 1. 

Page 378 : Describes .species as new under name of Tenthredo longicollia 
from vicinity of Paris, France. 

(4) Fabkicius, J. C. 

1787. MANTISSA INSECTORUM . . . Hafniae. Tome 1. 
Page 259, no. 19 : Brief description of Sirex tahidus. 

(5) VlLLERS, C. DE. 

1789. cAROLi LiNNAEi ENTOMOLOGIA . . . Lugcluni. Tome 3. 

Page 125, no. 135 : Record, as Tenthredo longicollis, from Europe. Page 
132, no. 13 : Short description of Sirex tahidus, with note, " Habitat 
in Angliae floribus." 

(6) LiNNfi, C. 

1790. SYSTEMA NATURAE . . . Ed. 13 (Gmelin), Lipsiae. Tome 1, pars 5. 

Page 2674, no. 18 : Short description of Sirex tahidus, with note, " Habi- 
tat in Angliae floribus." 

(7) Rossi, p. 

1790. FAUNA ETRUSCA . . . Liburni. Tome 2. 

Page 35, no. 739 : Records of Sirex tahidus from Italy. 

(8) Christ, Johann Ludwig. 

1791. naturgeschichte, classification und nomenclature dee insecten. 

' . . . Frankfort-am-Main. 535 p. Tab. 60, col. 
Page 416 : Sirex tahidus. 

(9) Fabeicius, J. C. 

1793. ENTOMOLOGIA SYSTEMATICA . . . Hafniae. Tome 2. 

Page 131 : Short description of Sirex tahiduf), from England ; original 
descriptJon of Sirex macilentus. 

(10) COQUEBEET, A. .7. 

1801. iLLUSTRATio icoNOGEAPHicA iNSECTOEUM . . , Paris. Tome 2. 

Page 48, Tab. 11, fig. 4 : Figure and brief description of Sirex tahidus^ 
from England. 

(11) Walckenaer, C. A. 

1802. faune parisienne, insectes. Paris. Tome 2. 

Page 46 : Record of Sirex tahidus from vicinity of Paris. 

(12) Klug, Fr. 

1803. MONOGEAPHiA siEicuM GEEMANiAE . . . Berlin. 83 p. 

Page 56, no. 8 : Generic transfer with description and synonymy of 
Astatus tahidus and note, " Locus in floribus." Page 55, no. 6, Tab. 
7, fig. 1 : Original description of Cephus analis. 

(13) Fabeicius, J. C. 

1804. SYSTEMA piezatorum . , . Brunsvlgiae. 439 p. 

Page 252, no. 6 : Transferred to Cephus tahidus with references to 
previous literature. Locality, England. 

(14) Latreille, p. A. 

1805. HISTOIRE NATURELLE . . . CEUSTACfS ET DES INSECTES. PariS. 

Tome 13. 
Page 144 : Record of Cephus tahidus as common around Paris. 



BLACK GRAIlSr-STEM SAWFLY. 15 

(15) Panzer, G. W. F. 

1805. FAUNA iNSECTORUM GERMANicAE . . . Nurnberg. Heft 85. 

Tab. XI : Figure of Astatus tabidus, references to previous literature and 
note, " Habitat in sylvaticis." 

(16) 

1806. KRITISCHE REVISION DER INSEKTENFAUNE DEUTSCHLANDS . . . 

Niirnberg. Bd. 2. 

Page 145 : References to previous literature on Cephas tabidus. 

(17) JuRiNE, Louis. 

1807. NOUVELLE METHODE DE CLASSER XES HYMENOPTSRES ET LES DIPTERES. 

Geneva. Tome 1. 
Page 72 : Description of Tnichelus luicmorroidaKs ; short description of 
Trachelus tabidus. 

(18) Latreille, p. a. 

1807. GENERA CRUSTACEORUM ET INSECTORUM . . . Pai'iS. Tome 3. 
Page 236 : Listed as Cephus tabidus. 

(19) Rossi, P. 

1807. FAUNA ETRUSCA . . . Helinstadii (Ed. Illiger). Tome 2. 

Page 53 : Brief description of Sirex tabidus with notes, " In Gallia 
raeridionali ..." " Hab. in fJoribus rarior." 

(20) Lepeletier DE St. Fargeiau, Am. 

1823. MONOGRAPHiA tenthredinetarum . . . Paris. 176 p. 

Page 19, no. 54 : Species described as new under name of Cephus 

mandibularis, with note, " In agro Parisiensi." 
Page 20, no. 55 : Species described as new under name of Cephus 

nigritus, with note, "An mas Cephi mandibularis?" 
Page 20, no. 57 : Description of Cephus tabidus with references to 

previous literature. 

(21) Audinet-Serville, J. G. In: Vieiixot, Lepeletier, etc. 

1828. faune francaise . . . Paris. Hymgnopteres, 
Page OG, no. 5 : Cephus mamlihularis. 

(22) Curtis, John. 

1830. BRITISH entomology . . . London, v. 7. 

Plate 301 (accompanying text) : Trachelus tabidus recorded on flowers 
and grass in fields of Dover and Southgate, England. 

(23) Stephens, J. F. 

1835. illustrations of British entomology . . . Mandibulata. Lon- 
don. V. 7. 

Page 106, no. 9 : Description of Cephus tabidus; found in Hertford, 
Cambridge, Whittlesea Mere, Dover, Southgate, England. 

(24) Hartig, Theodor. 

1837. Die Familien per Blattwespen und Holzwespen . . . Berlin. 

416 p. 

Page 363 : Description of Cephus tabidus. 

(25) Blanchard, C. E. 

1840. HisTOiRE naturelle des insectes . . . Paris. Tome 3. 

Page 224, no. 3 : Description of Cephus mandibularis; no. 4 : Descrip- 
tion of Cephus tabidus; found near Paris. 

(26) Herrich-Schaffer. G. A. W. 

1840. nomenclator entomologicus. Regensburg. Heft 2. 
Pages 92-93 : Lists synonymy of Sirex taibidus. 

(27) Lucas, H. 

1849. HISTOIRE naturelle des animaux articul^s. Pars 3. Insecte»- 
. . . Paris. In Exploration Sci. de I'Algerie . . . 1840, 1841, 1842.. 
Page 342 : Records Cephus tabidus taken in May in Constantine. 



16 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

(28) Costa, A. 

1860. FAUNA DEL EEGNO Di NAPOLi . . . NapoU. Iiuenotteri, 
Page 8 : Cephus tabidus. 

(29) Dum6ril, a. M. C. 

1860. ENTOMOLOGiE ANALYTiQUE. Paris. 1339 p. 

Page 980 : Note that larvae of Sirex tabidus live in stems of grain. 

(30) Damianitsch, Rudolph. 

1866. HYMENOPTEROLOGiscHE BEiTRAGE. In Verli. Zool.-Bot. Ges. Wien, 
Bd. 16, p. 993-996. 

Pages 993-995 : Original description of Cephus crheri, taken at edge of 
barley field in Syria. 

(31) Taschenberg, E. L. 

1871. einige neue siJDEUEOPAiscHE HYMENOPTEajA. Ill Zeitschr. f. d. 
Ges. Naturw., Bd. 4 (n. s. ). 
Page 306 : Description of Cephus tahidus ; found in Island Lesina. 

(32) Cost A, A. 

1878. RELAZIONE DI UN VIAGGIO PEE L'EGITTO, LA PALESTINA, E LE COSTE 
DELLA TURCHIA ASIATICA PER RICERCHE ZOOLOGICHE. In Atti ACC. 

Sci, Napoli, v. 7, no. 2. 

Page 14 (footnote) : Species described as new under name of Cephus 
vittatusj from Egypt. 

<33) ANDRfi, Ed. 

1881. SPECIES DES HYMfiNOPTEREs d'europe et d'algerie . . . Beaune, 
Cote-d'Or, Tome 1. 

Page 535, no. 31: Description of Cephus taMdtts ; found in England, 
France, Spain, Switzerland, Algeria, Italy, Germany, Syria. 

<34) Cameron, P. 

1886. A synopsis of the British species of cephina. In Ent. Mo. 
Mag., V. 22, p. 17.5-177. 
Page 177: Brief description of Cephus tahidus j synonymy; table. 

<35) 

1890. A MONOGRAPH OF THE BRITISH PHYTOPHAGOUS HYMENOPTERA. 

London, v. 3. 

Page 120, no. 6, PI. 3, flg. 9 : Description, previous references in litera- 
ture, and synonymy of Cephus tabidus. Found In England, Sweden, 
Germany, Spain, Italy, N. Africa, Syria. 

(36) Magretti, P. 

1890. imenotteri di siria . . . In Ann. Mus. Civ. Stor. Nat. Genova, 
(2) V. 9, p. 522-548. 
Page 528 : Cephus tabidus recorded from Europe, Algeria, Syria. 

<37) Costa, A. 

1894. prospetto sistematico degli imenotteri italiani. Napoli. Pars 3. 
Page 253 : Cephus tabidus recorded from Italy and Sicily. 

(38) Dalla Torre, C. G. de. 

1894. CATALOGUS HYMENOPTERORUM . . . LlpSiae. V. 1. 

Page 412 : Bibliographic catalogue of Cephus tabidus. 

(39) [AsHMEAD, W. H.] In Smith, J. B. 

1900. insects OF NEW JERSEY. In Ann. Kept. Sta. Bd. Agr., Suppl., 1899, 
p. 501-615. 
Page 600: Species listed as Calamenta [Calameuta] johnsoni. 

<40) ASHMEAD, AV. H. 

1903. TWO NEW PHYTOPHAGOUS HYMENOPTERA. In Can. Ent., V. 35, 
p. 233. 

Page 600 : Species described as new under name of Calmeuta johnsoni, 
from Riverton, New Jersey. 



BLACK GRAIlsr-STEM SAWFLY. 17 

(41) KONOW, Fk. "Vv. 

1904. SYTEMATISCHE ZUSAMMENSTELLUNG . . . ChalastOgastra. Ill Zeitschi'. 
Hym. Dipt., v. 4, p. 225-288. 

Page 256 : Description and synonymy of Trachelus tahtdus. Found 
in South and Middle Europe, North Africa, and Asia Minor. 

(42) 



1905. hymenopteka: family lydidae. In Wystman, P., Genera In- 
sectorum, Fasc. 27. 

Page 20 : Synonymy of Trachelus tabidus. Found in South and Middle 
Europe, North Africa, and Asia Minor. 

(43) RXJDOW, F. 

1909. LEBENSWEISE DEE HOLZWESPEN, siBiciDAE. In Intern. Ent. Zeitschr., 

Jahrg. 3, p. 123-124. 

Page 124 : Record of Trachelus tabidus from South Europe. Also 
records of host plants which are doubtful. 

(44) KOKUJEV, NiKITA. 

1910. SUE LA DISTraBUTION DES EEPEESEKTANTS DE LA SOUSFAMILLE DES 

CEPPIINI KONOW ... EN EUSSIE ET LA DESCEIPTION DES ESP:&CES 

NoiTV^ELLES. Iti Rev. Russ. Ent., v. 10, p. 127-189. 
Page 137 : Trachelus tabidus. 

(45) [MacGillivray, A. D.] Iti Smith, J. B. 

1910. EEPOET OF THE INSECTS OF NEW JERSEY'. Iti Ann. Rept. N. J. Sta. 
Mus., 1909. 

Page 595 : Synonymizes Calamenta [Calameuta] johnsoni and repeats 
record of occurrence in Riverton, New Jersey. 

(46) Kholodkovsky, N. 

1912. a course in entomology theoretical and practical. pctro- 

grad. V. 2. 

Page 472 : Trachelus tabidus. 

(47) KULAGIN, N. M. 

1918. THE PEINCIIAL INSECT PESTS OF FIELD CEOPS IN EUROPEAN RUSSIA 

FOR THE LAST TWENTY YEAES. Iti Yearbook Dept. Agr. Centr. 
Bd. Land Admin, and Agr. Petrogi-ad. v. 6, p. 585-688. (Rev. 
Appl. Ent., ser. A, v. 2, 1914, p. 201-202.) 
Records Trachelus tabidus from 26 governments ; more frequent and 

injurious in southern governments. Damage about 14 to 20 per 

cent, sometimes more. 

(48) KURDJUMOV, N. V. 

1913. THE MORE IMPORTANT INSECTS INJURIOUS TO GRAIN CEOPS IN MID- 

DLE AND SOUTH EUSsiA. In Studies from Poltava Agr. Exp. Sta., 
no. 17, Dept. Agr. Ent., no. 6, 119 pp. (Rev. Appl. Ent., ser. A, 
V. 2, 1914, p. 170-173.) 
Trachelus tabidus from South Russia on rye. 

(49) SHTrHEGOLE\-, I. M. 

1913. REPORT ON INJURIOUS INSECTS AND DISEASES OF PLANTS IN THE 
GOV'EENMENT OF TAUEIDA DUEING THE YEAE 1912. In Rept. ASS't. 

Ent. of Govt, of Taurida, Simferopol, p. 24-56. (Rev. Appl. Ent., 
ser. A, V. 1, 1913, p. 357. ) 

Records Cephus tabidus as having attacked 15 to 20 per cent of the 
wheat crop. 



18 BULLETIN 834, U. S. DEPARTMENT OF AGRICULTURE. 

<50) UvAROV, B. I'. 

1914. KEPOKT OF THE ENTOMOLOGICAL BUREAU OF STAVROPOL FOE 1913. In 

Dept. Agr. Centr. Bd. Land Admin, and Agr. Petrograd. 86 p. 

(Rev. Appl. Ent., ser. A, v. 3, p. 44-^7.) 

Records Trachclus tdhidtis injuring wheat ; not determined if more 

injurious than Cephus pygmacus as differences in larvJB are still 

unlinown. 

(51) Corey, E. N. 

1914. INSECT PESTS OF 1914. Ill Kept. Md. Sta. Hort. Soc, v. 17, p. 

104-112. 

Page 106 : Records Cephus pygmaeus injuring wheat at Germantown, 
Md. (Undoubtedly a misidentification of Trachelus taMdus.) 

(52) BOEODIN, D. 

1915. CEPHUS PYGMAEUS L., ON THE WESTERN EXPERIMENTAL FIELD OF 

THE AGRICULTURAL EXPERIMENT STATION OF STAVROPOL, CAUCASUS. 

In Husbandry, Kiev, p. 876-883. (Rev. Appl. Ent., ser. A, v. 4, 

1916, p. 21.) 

Records Trachehis tahidut infesting stubbles of barley, and winter and 
spring sown wheat in Stavropol. 

(53) ZOLOTAREVSKY, B. N. 

1915. PBELIMINAEY KEPOKT ON THE WORK ON ENTOMOLOGY IN 1914. In 

Stavropol-Caucasian Agr. Exp. Sta., Stavropol. 12 p. (Rev. 
Appl. Ent., ser. A. v. 3, 1915. p. 479-480.) 

Records Trachelus taMdus as appearing later than Cephus pygmaeus, 
and chiefly found on summer-sown crops. 

(54) UvAROv, B. P., & Glazunov, V. A. 

1916. REPORT ON THE WORK OF THE ENTOMOLOGICAL BUREAU OF STAVROPOL 

FOR 1914. In Dept. Agr., Ministry of Agr., Petrograd, p. 13-54. 
(Rev. Appl. Ent., ser. A, v. 4, 1916, p. 460.) 

Records large outbreak of Trachclus tahidus in 1914, with large numbers 
of parasites. 

(55) MAcGiLi.miAY, A. D. 

1917. HYMENOPTERA OF CONNECTICUT. Part 3. Tenthredinoidea. In 

Bull. 22, Sta. Geol. & Nat. Hist. Survey, Conn. 
Page 174 : Description of Tra-helus tabidus. 

(56) Howard, L. O. 

1918. EEPOBT OF THE ENTOMOLOGIST, hi U. S. Dept. Agr. Annual Repts. 
24 p. 

Page 7 : Record of Trachelus tabidus injuring winter wheat in Northern 
Virginia, and throughout Maryland and Pennsylvania. 



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